http://cyclechat.co.uk/forums/showthrea ... ost&page=9
Real good discussion...
Page 9, the Chap gets the post unstuck. You can read how.
Those interested should read the whole thread.
What method used depends on whether you are using Carbon on Carbon (not me), Steel Frame, Aluminum Post, Steel on Steel, etc.
The above reference is steel frame, aluminum post and his final solution is a bit drastic with pictures there.
Steel on Steel, I'd just lubricate it with a fine penetrating oil.
The white lithium grease is an interesting twist as well.